1. Field of the Invention
The present invention relates to a castor and, more particularly, to a castor for a wheeled vehicle, such as a chair, cart, medical bed and the like.
2. Description of the Related Art
A conventional castor comprises a wheel frame, a roller rotatably mounted on the wheel frame, and a braking plate mounted on the wheel frame and movable to press the roller so as to brake the roller. However, the distance between the braking plate and the roller is fixed and cannot be adjusted so that when the wall thickness of the roller is reduced due to rubbing or wearing during a long-term utilization, the braking disk cannot rub and brake the roller efficiently, thereby decreasing the braking effect of the braking disk.